Calculate mean instead of average

[J Webster]

Is there a way to work out the most common max reading pf the indicator?

Alternatively, how can I get a mving average top show on this indicator window?

...or last option a bollinger band around the indicator?

//+------------------------------------------------------------------+
//|                                                 AvDistFromMA.mq4 |
//|                      Copyright © 2011, MetaQuotes Software Corp. |
//|                                        http://www.metaquotes.net |
//+------------------------------------------------------------------+
#property copyright "Copyright © 2011, MetaQuotes Software Corp."
#property link      "http://www.metaquotes.net"

#property indicator_separate_window // Indic. is drawn in a sep. window
#property indicator_buffers 1       // Amount of buffers
#property indicator_color1 Red      // Line color
 
double Buf_0[];                     // Indicator array opening
//--------------------------------------------------------------- 2 --
int init()                          // Special init() function
  {
   SetIndexBuffer(0,Buf_0);         // Assigning the array to the buffer
   SetIndexStyle (0,DRAW_LINE,STYLE_SOLID,2);// Line style
   SetIndexLabel (0,"High/Low Difference");
   //SetLevelValue (0, 0.0010);       // The horizontal line level is set
   //SetLevelValue (1,-0.0010);       // Another level is set
   return;                          // Exit from spec.init() function
  }
//--------------------------------------------------------------- 3 --
int start()                         // Special start() function
  {
   int i,                           // Bar index
       Counted_bars;                // Amount of calculated bars 
 
   Counted_bars=IndicatorCounted(); // Amount of calculated bars 
   i=Bars-Counted_bars-1;           // Index of the first uncounted
 
   while(i>=0)                      // Cycle for the uncounted bars
     {
      double MA100 = iMA(NULL, PERIOD_H1, 100, 0, MODE_SMA, PRICE_CLOSE, i);
      Buf_0[i]=MathAbs(Close[i]-MA100);      // 0 value of the buffer on bar i
      //if(Open[i]>Close[i])          // if the candle is black..
      //   Buf_0[i]=-Buf_0[i];        // .. then reverse the value
      i--;                          // Index calculation for the next bar
     }
   return;                          // Exit from spec.start() function
  }
//--------------------------------------------------------------- 4 --

[J Webster]

anyway I can get a bollinger band around an indicator calc in a separate window?